In recent years there has been a move towards so called renewable energy sources, such as wind and wave power, but wind turbines have a very high visual impact and are, of course, dependent on there being wind. Wave powered generating apparatus has proved difficult to realise effectively for a variety of reasons, not least the generally large costs associated with equipment required to withstand the power of extreme waves that occur during storms.
Tidal energy, on the other hand, is based on a guaranteed energy source, that of the movement of the tides. A great number of tidal powered generating apparatus have been proposed over the years including, for example, International Patent Publication No. WO 88/04632, U.S. Pat. No. 3,986,787, DE 2648318 and U.S. Pat. No. 3,922,012.
The devices of the prior art have generally consisted of very large constructions which have depending from their underside, propellers or turbines which are driven by the motion of tidal currents passing therethrough. Such devices may be floating devices, such as that described in WO88/04632 or submersed (on the seabed) devices such as that described in U.S. Pat. No. 3,922,012.
All of the prior art apparatus known to the inventor suffer from a number of inherent problems, including large and sophisticated designs which do not lend themselves to simple manufacturing techniques and which are prone to damage i.e. they have poor survivability in the sea; and/or are difficult to maintain/repair without the need for expensive handling or installation equipment; and/or required to be “piled” into the seabed.